Dust protector cap for percussive hammers



July 12, 1960 F. A. WERSTEIN DUST PROTECTOR CAP FOR psacusszvs HAMMERS Original File Sept. 3, 1957 at 014166 2 W/Wm 2 4 the shell.

United Se Patent 1 2,944,523 DUST PROTECTOR CAP FOR Frank A. Werstein, Long Beach, Ind. 7 Original application Sept. 3, 1957, Ser. No. 681, 689,

now Patent No. 2,918,290, dated Dec. 22, 1959.; Di- 1 vided and this application Apr. 2, 1958, Set. No.

2 Claims. Cl. 121-32 This invention relates generally to percussive hammers and more particularly, relates/to a novel protective cap for preventing fine particles. and dust from entering .the tubular end of the hammer during operation; of thehammer. A

This. is. a division of application .Serial .No. 681,689 filed September 3, 1957, now Patent No.f2,9 18,290,for the invention entitled Chuck and Adapter for Self-Drilling Expansion Shells.

In the application ofwhich' drilling expansion jshell, Such a. shell comprises a hol w cylindrical member having sharp axially directed teethat one end and having its opposite end tapered to enable. the member to be mountedin a socket provided in 3 mer delivers its blows. iTheshell teeth drill a hole in PERCUSSIVE 7 7 5 shells in concrete ormasonry, regardless of the chuck mounted'to the tubular end of the hammer. "A further object of the invention is to provide a combined structure of a chuck for anchoringself-drilling eitpansion shells and a protective cap associated with said chuck which will prevent entry of dust and particles into' which the" the operative end of the percussive hammer to chuck is mounted.

gAnother-object of the invention is to provide a protective cap of the character described which'is formed of a resilient, material having an opening at one endof an internal diameter enabling the cap to be engaged on.

. ferred form has been set forth as required by the patent law order especially to pointjout wherein a substantial j a insia lt imi vention related to ia noveliholder for a'so-called jself a chuck. Shells of this, construction 'arejshown' and advance has been made drawings: I

parent application'sand having aself drilling ei pansion shell, 1 portions of which are in section, seized'therein stalled on a percussive hammer.

'and'the dust protector"cap/embodying this invention; in.

.Fi'gzj2'is' a similar'view, but illustrating the same in,

section,'and in-this viewihe, shellhas been fully driven into the masonry. In this vievv as well as the'previousf view, only a fragmentary portion of the hammer is shown.

Figs. 3 and 4 are transverse sectional views taken along the lines 3-3 respectively of Fig. 2 andin the indicated direction.

the masonry and the debris and cuttings pass through the.

hollow center of the shell andout of a passageway provided in thechuck. Thus, the anchoring of such ex pansion. shells in concrete, masonry and stonejalways is accompanied by ejection .of particles and dust from There are a great manyconstructions for. percussive hammers and a greatmany constructions for chucks for mounting on the operative end of the hamrnen. In'my parent application, there was provided a. combined structure of a tool holder and adapter which was referred to as a chuck and ad apten when mentioned together in said application andasateol holder aiid adapter when referred to separately; Also, there was'described and illustrated a chuck of'heretoforeknownconstruction for use with'such self drilling'eiipansion shells, suchchuck having a Shahkbfstm' which'is inserted intothepercussive hammer'withwliichthe same is to be used. In thecaseiofeithf the prior art chucks or the combined structure ofthe'tool holder'and adapter disclosed said parent applicati'orifthe' 'efiluit 6f particles and dust from the shell during'the anchoring 'operation colild'enter through the operativeend: of therpercussive hammer to clog. and j am,the same or harrn:wgrking components thereof by abrasion. "'It is therefore a principal object of this invention to provide .a novel protective cap for'use with percussive hammers to prevent such particles and dust from entering the operative end of the hammer 7 during the drilling process.

V capable of substantially universal use in connection with percussive hammers for anchoring self-drilling expansion 'which is intended to telescope over the end of the ham- The head has an axiall tapered socket 2i) opposite. sh ank 12, torreceive. the self-drilling shell, and the'socket com municatesf with I a transverse passageway 22. which is for. p 'r o ejqf ermi l n s br nd' ngs dr l e o t, ofthehole i formed, by the, shell to be' worked out, and; fonthe additionalpurpose "of'admitting 'a'shell' ejector .01 bail 26 used to oscillate or swing the chuck 10 Fig. 5 is an elevationa'l view, partially in section,'to show a chuck of previous construction, comprising, prior It is considered that the dustprotector' cap embody ing this invention can be employed either with the combined structure ofthetool holder and adapter described and claimed in the parent application, or with fknown chuck structu res, such as illustrated in Fig. a Referringto Fig. 5, the reference character ltlidentifies a chuck of heretofore known design, said chuck having a shank or stem 12 which is inserted into the.

percussive hammerwith which the same is' to be used.

The particular structure which includes the annular groove 14 is especially intended for use with the electric V hammer illustratedin US. Patent 1,968,055 and US.

Patent 2,767,988.

The shank lz is integral with an enlarged diameter head 16 the end .ofwhichhas an undercut groove 18 mer to prevent the admission of dust into the hammer.

tool. Spaced axially rearward .of the passageway'22 is another transverse passageway 24 preferably at right angles to' passageway 22 into which is journalled the oppositely facing ends of a looped rod-forming a handle as the drilling operation proceeds.

The chuck l0 is a typical structure, and of moment to this invention is the enlarged diameterof head 16 which Patented July 12, 11960.

in thearts and sciences. In-the' is provided with an undercut groove 18. As explained in my parent application, the head 16 was the thickest part of the chuck, and in the fabrication thereof, considable waste of material cut away during formingof the chuck was a disadvantage. formed with head diameterssubstantially reduced, the undercut groove 118 must of necessity be eliminated. This invention eliminates any need for such groove 18 to pre vent-admission of dust to the hammer and thereby further encourages such reduction in the diameter of a head on the chuck, such as head 16.-

Figs. 1 and 2 illustrate the combined structure of .the tool holder and adapter of the parent. application and with which the dust protector cap of thisinvention may be utilized. Instead of an integral chuck 10, there are formed two parts, namely, a. tool. holder 30 and an adapter 32. The tool holder comprises a cylindrical member 34 having one end, the left in the figures, provided with an axial socket 36 of such dimensions to receive the tapered end 38 of a self-drilling shell 40' of a predetermined size. The right hand end of the cylindrical member has another socket-42 of tapered formation, so

dimensioned to receive the male tapered end 44 of the adapter 32.

The tool holder also is provided with a tapered passageway 46 which passes completely through the cylindrical member =34 and may receive the ejector tool shownin fragmentary outline 48 in 'Fig. 2. Since the self-drilling shell is hollow, asit is hammered and drilled into ward end and fracture grooves 62 adjacent said end for well known purposes. The shell 40 is intended to be driven into masonry 50 and have its tapered end. 38

broken off by lateral strain. The annular fracture groove 66 provides a weakened area at which the fracture occurs.

The hammer identified. by reference character 58 includes a structiu'e for mounting the adapter 32. or the chuck 10 of Fig. which is described in considerable detail and claimed in U.S. Patent 2,767,988, which is owned by the assignee of this application. There is a reciprocating plunger 68 which imparts blows to the impact end of the shank 70 of adapter 32 or where the chuck is used, to the impact end of the stem 12. The shank 70 has an annular groove 72 spaced from the impact end 74, the axial length of which controls the stroke of the hammer, being confined to its reciprocating movement by the key 76. The key '76 is confined in slot 78 formed in the tube 80 of the hammer and locked in place by telescopically slidable sleeve 82 which covers the same and is pressed against the stop ring 84 by the spring 86. It may be noted that chuck 10 has groove 14 which would likewise be so engaged by the key 76 if chuck 10 were being mounted to the operative end of hammer 58.

The dust protector cap embodying the invention is designated 92 in Figs. 1 "and 2. The member 92 'is formed of some soft resilient material, such as rubber or the like, as a cup-shaped member which opens at one end thereof Where such. chuck is toward the hammer 58, with its internal diameter being such that it can be engaged upon the free end of the tube 80 of the hammer. Adjacent the forward end of shank 70 there is provided an annular groove 88 and said groove seats the annular lip 90 provided by an aperture in the opposite end of the cup-shaped member 92. It may be noted that the diameter of said aperture is less than that of the opposite open end of'the cup member. Said member 92 therefore provides a resilient and substantially dust tight connection so thatdust, debris and particles of masonry, cement or stone in which the shell 40-is embedded cannot enterthe tube 80- and cause damage to the partsof'the hammer 58 by abrasion. The

dust cap 92. may be provided as-part of the adapter 32, or as part of a chuck such as identified by the numeral 10 which has beenprovidedwith. a groove, such as annular groove 88 for seating the lip 90.

It is believed that no further explanation is necessary, but it is emphasized that variations in the size, proportions and minor details of said dust protector capmay be made without. departing from the spirit or scope of the invention as defined. in .the vappendedclaims.

What it is desired to secure by Letters Patentof .the United States is:

1. In a device of the character described and including a percussive hammer having a tool-holding sleeve protruding from the hammer, a tool operatively engaged on if: the interior of the sleeve. and readily removable therem-asonry 50, the stone dust and debris particles will work from, a cylindrical member .ofresilient material having an open end thereof re'movably disposed'on the exterior surface of the sleeve in substantially dust-tightengagement therewith, a. readily separable lip and groove con- :nection between the cylindrical member and the tool to enable the cylindrical member to reciprocate with the tool and simultaneously along the exteriorsurfaceof the tool-holding sleeve during operation and be carried by the tool when the tool. is removed from the tool-holding sleeve the. cylindrical member sliding off said sleeve in the latter instance.

2. In a device of the character described and including a. percussive hammer having a tool holding sleeve protruding from said hammer, a tool operatively engagedon the interior of the sleeve and readily removable therefrom, a dust-protector cap comprising a cylindrical member of resilient material having an open end. tightly engageable with the exterior surface of said sleeve in substantially dust tight relationship, said member having a peripherallip portion at itsother end engageable with said tool, said member being adapted for reciprocal movement with said tool, the upper. portion of said member adapted for simultaneous reciprocal movementalong the exterior surface of said .sleeve.

References Cited in the file;of this patent UNITED STATES PATENTS Germany Mary 9, 1928 

